Numerical Investigation of Crack Development and Internal Force Networks on Intact Rocks

Abstract

The structural integrity of underground excavations, resource extraction processes, and the overall safety of geotechnical operations hinge on a comprehensive understanding of brittle rock failure mechanisms and the distribution of internal stress within these formations. This research sheds light on the underexplored aspects of geomechanics, showing the complexities of brittle rock behavior under stress, specifically focusing on the internal force distributions that precipitate failure. This thesis consists of three parts. First, validating the efficacy of the Bonded Particle Method (BPM) through the simulation of elastic wave propagation in response to a single point force excitation. This verification process underscores the method's reliability and accuracy, establishing a solid foundation for its application in subsequent analyses. Second, the BPM is applied to create a Particle Flow Code (PFC) 2D model of Lac du Bonnet granite. We demonstrate the material genesis procedures, model calibration, and delineate the general characteristics of the granite model and showcase the practical application of the BPM in understanding rock behavior. Third, we explore the rock failure and internal force networks within brittle intact rocks. We investigate the crack development under compressive loading, discover five distinct internal force networks and critical angles within the cemented granular system, and find that the failure occurs along the force subgroups with high force gradient. This thesis represents a stride forward in geomechanics, offering a comprehensive analysis of brittle rock failure mechanisms that bridge theoretical concepts with practical applications.